Identification and characterization of polyphenols from aqueous extract of Tectona grandis Linn leaves obtained at pilot plant scale

Tectona grandis L. (Verbenaceae), commonly named teak is used in folk medicine for a wide variety of remedies. A pilot plant coupled-process was developed mimicking the traditional recipes using plant leaves to prepare functional and active polyphenol extracts with antioxidant properties. Polyphenols and antioxidants from dried leaves of T. grandis leaves were extracted by Ultrasound-assisted extraction. Cross flow microfiltration coupled with Reverse Osmosis (clarification/concentration of crude extract) were used to stabilize crude extract obtained. Polyphenol contents of the co-products were quantified at 760 nm using spectrophotometric method [1]. Their antioxidant capacity was measured according to ORAC method [2]. LC-MS was used to characterize phenolic compounds. The ultrasound-assisted extract of T. grandis leaves obtained in pilot scale was clarified by cross flow microfiltration and then concentrated by reverse osmosis. The concentration factors of polyphenol and antioxidant capacity were 18 and 21; respectively. Statistical analysis indicate that clarification/concentration process did not degrade polyphenols and antioxidant activity from T. grandis leaves, as found by Adje et al. [3]. HPLC-DAD profile of polyphenols from RO concentrate extract permeates to identify twenty phenolic compounds. The four major phenolic compounds were characterized by LC-SM in concentred aqueous extract of T. grandis leaves [4]. Verbascoside (Anti-hyperglycemic compound)[5] was identified as the most abundant phenolic compound. The Process used to eco-friendly extract and concentrate bioactive water-soluble molecules, such as polyphenols, from T. grandis, traditionally used by village people in Cote d’Ivoire, allowed producing natural concentrates. The most abundant polyphenolic compound was identified as verbascoside which could be benefit to human body.(Texte integral)